The present application relates to electrophotographic printing. More specifically, the application relates to a system and method for calculating an amount of toner in a toner container located within a electrophotographic printing machine.
In the well-known process of electrophotographic printing, a charge retentive surface, typically known as a photoreceptor, is electrostatically charged, and then exposed to a light pattern of an original image to selectively discharge the surface in accordance therewith. The resulting pattern of charged and discharged areas on the photoreceptor form an electrostatic charge pattern, known as a latent image, conforming to the original image. The latent image is developed by contacting it with a finely divided electrostatically attractable toner which is held on the image areas by the electrostatic charge on the photoreceptor surface. Thus, a toner image is produced in conformity with a light image of the original being reproduced. The toner image may then be transferred to a substrate or support member (e.g., paper), and the image affixed thereto to form a permanent record of the image to be reproduced.
The electrophotographic process is useful for light lens copying from an original as well as printing electronically generated or stored originals such as with a raster output scanner (ROS), where a charged surface may be image wise discharged in a variety of ways.
Existing electrophotographic printing machines are commonly supplied with replaceable containers which hold the toner. Typically, such a container is positioned horizontally within the printing machine, and therefore gravity does not ensure movement of the toner towards the latent image. Thus a mechanism, such as an auger, is needed to move the toner. One particular container design is a cylindrical container having an opening near one end and internal spiral ribs, which when rotated urges the toner to the opening. Such containers are also called bottles or cartridges among other names.